This invention relates to new and useful quinazoline and isoquinoline compounds. More particularly, it is concerned with a novel series of 4-piperazino-6,7-dialkoxyquinazolines and 1-piperazino-6,7-dialkoxyisoquinolines, which are of value in the field of medicine in view of their beneficial therapeutic effects.
In the past, various attempts have been made by a few investigators in the specialized field of organic medicinal chemistry to obtain new and useful bronchodilators, i.e., therapeutic agents which will cause bronchodilation without adversely affecting the treated subject. In one instance, this has involved the synthesis and testing of several 2- and 4-piperazino-6,7-dialkoxyquinazoline compounds, including the corresponding isoquinolines, such as those already disclosed in U.S. Pat. No. 3,517,005. However, in the search for still newer and better or more improved bronchodilators, little is known about the effect of certain 4-carbamyl substituents on the piperazine ring moiety of the aforesaid quinazoline and/or isoquinoline compounds in this area.